Feature 1Using Good Glass: Having been through excellent workmanship, the optical glass comes with high accuracy to largely improve the measurement. 2Clear Reflection: Designed to have 17mm constant and 25.4mm effective diameter, the mini surveying prism ensures clear image in reflection. 3Great Durability: The lens is fully covered by sturdy ABS plastic housing, which has great durability against wearing and long term use. 4Wider in Utility: Suits for Trimble and other measuring instrument, the prism can be used on the testing of tunnels, subways, mines, etc. 5Easy Installation: The clear thread inside the brass adapter blow enables the prism to easily connect to 5/8in x 11 threaded rod or tripod.Item Type: Total Station PrismMaterial: ABSGlass Diameter: Approx. 25.4mm / 1inPrism Constant: -17mmApplication: For the testing of tunnels, subways, mines, highways, etc. Suitable for measuring instruments such as for Trimble.Usage: Widely used in various industries such as subways, railways, tunnels, dams, steep slopes, etc. .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Total Station Prism